Many pharmaceutical container closure systems, and particularly prescription container closure systems, often include a “child resistant” mode of operation, and sometimes both “non-child resistant” and “child resistant” modes. While these types of closure systems are generally very effective in preventing a child from opening the closure in the child resistant configuration, it is not impossible for children to open them (hence the name “child resistant”). In particular, a child playing with this type of closure system may sometimes be drawn to certain locking/unlocking features, such as a push-down tab, visible on the cap resulting in the child unintentionally removing the cap from its container. Also, particularly in the case of push-down-and-turn child resistant closures, the child may even figure out how to remove the closure by simply watching their parents, or even reading instructions displayed on exterior of the closure, and then being able to do so on their own. Accordingly, what is needed, at least as an option for consumers that have young children in their household, is a “child proof” closure system.
While many “lock-and-key” type closure systems are disclosed in the prior art in an attempt to provide an effective “child proof” closure system, no such systems have been commercialized, at least on any significant scale. This is likely due to weakness of the designs that have been introduced so far, including designs that would not be effective in actually preventing children from being able to open the containers and designs having flaws that would make the closure systems expensive to manufacture and/or impractical from a commercial standpoint.
For example, U.S. Pat. No. 6,032,811 provides a cap assembly having an outer cap member and an inner cap member each having a key slot. While the outer cap is designed to rotate independently of the inner cap, a key may be inserted into the key slots to turn the inner cap when the key slots are aligned. One of the many problems with this overly simplistic design is that the key actually comes secured to the cap, the slot on the outer surface of the outer cap is clearly visible, and the slot is configured such that ordinary household items could be inserted into the slot. Accordingly, just like children toys that teach toddlers motor skills by inserting different shapes into different slots, certain children playing with the closure could end up inserting the key or other household object into the slots. Once the key is inserted correctly, whether intentionally or not, it is very likely that the child would be able to open the container. The prior art includes many other closure systems that suffer these same deficiencies. In fact, many of the systems are actually designed such that normal household items may be used to open the closure system, such as U.S. Pat. No. 3,396,864 patent, further described below, which includes a slot designed to be used with a coin. What is needed therefore is a more discrete locking system that makes it more difficult for a child to recognize or understand how to open the closure system or otherwise prevents attracting child actions that result in the child unintentionally opening the container.
Similarly, U.S. Pat. No. 3,485,402 provides a cap assembly with two opposing key hole openings in the outer cap operable to be aligned with opposing key holes on the inner cap for engagement with a key having opposed prongs. The openings of the inner and outer cap were not designed to be discreet but to allow the key to traverse the center of the cap that includes a screw to secure the inner cap within the outer cap. This design suffers several critical flaws, most critical of which is that an additional gasket (i.e., additional expense and complexity) is needed to prevent air, moisture, leakage, etc. from coming into or escaping the container opening due to the key holes of the inner cap and the screw that is inserted through the outer and inner caps. Further, the gasket extends into the opening of the container such that, like the '864 Patent described below, the '402 Patent does not permit induction sealing. Also, due to the key having to traverse, the screw extending from the outer cap, pushing down on the key to insert the key prongs into the key holes with the handle would actually pivot the prongs out of the key holes.
Additionally, like the gasket and screw of the '402 Patent, many of the prior art “child proof” closure systems include numerous parts, which adds thickness and cost to manufacturing the cap. For example, U.S. Pat. No. 4,796,768 describes a lockable closure cap that requires a standard type key, springs, cams, etc. to lock the closure to the container. As would be expected, this type of closure, while requiring a specialty key, would be expensive to manufacture. Further, all the various parts required to provide use of a standard key design results in a large and unattractive size for the closure and prevents the closure from being applied to a container in an automated dispensing system.
U.S. Pat. No. 3,396,864 and European Patent No. 06311945 disclose other locking caps having ratchet ramps on both the outer cap and inner cap that allow the closure assembly to be screwed onto a container when the outer cap is rotated in a clockwise direction but is designed to prevent the closure from being removed without a key when the outer cap is rotated in the counter-clockwise direction. While it is desirable in certain instances to be able to provide a closure that can be screwed onto a container but requires key to remove the closure, the '864 Patent is silent as to how this would be accomplished other than including ramps on both the inner cap and outer cap. Additionally, like many of the other locking closures of the prior art, including the '811 Patent described above, the key slots/indentions of the cap portions are centrally located in the '864 Patent and '945 Patent. This requires a pocket to be formed that extends into the interior space of the inner caps. The pocket is formed due to the needed depth of the slot of the inner cap that is configured to receive the key and prevents the opening of the closure from being lined in an induction sealing process as known in the art. Further, the pocket results in additional resin being needed to form the cap, adds needless weight to the cap, and slows down the molding/cycle time required to make the closure.
In another aspect, many closure systems, particularly those designed to be child resistant, are difficult to open and close for the elderly as well as those with arthiritic hand conditions. Thus, while it would be beneficial to provide a multifunctional key that not only unlocks the closure system but also assists a user in both screwing the closure system on and off a container, the prior art has generally ignored this aspect when designing the interaction between the keys and the closure systems. For example, the '864 Patent, '945 Patent, and '402 Patent described above provide locking closure systems in which the key engages a recess centrally located within the inner cap. Thus, the key is unable to provide much additional torque than what would already be supplied by a user that just rotates the outer cap upon engagement with the inner cap.
Further, likely because the locking closure systems of the prior art did not recognize or otherwise were unable to successfully implement a closure system in which the key provided an appreciable mechanical advantage in screwing the closure system on and off a container, none of these systems describe a closure having both a child resistant option and a key option. Such a system is advantageous in numerous situations. For example, both options may be preferred for elderly patients that have trouble opening and closing child resistant closures but also have caregivers that often dispense their medications. Thus, the elderly individual may desire a tool that assists in screwing the closure on and off a container, while the caregiver may wish to open the container using the normal child resistant function. Also, both options would be beneficial when a child resistant cap is secured to a container in automated dispensing systems. In this regard, workers required to perform spot checks of prescriptions that are dispensed in these automated systems must screw on and off countless child resistant caps, and, thus, often complain of hand pain and carpal tunnel symptoms. Providing these workers with a tool to quickly assist them in screwing on and off these child resistant caps would thus be beneficial. Also, liquid pharmaceuticals often result in the sticky pharmaceutical being spilled onto the driving structures of child resistant caps, making such structures generally ineffective. By providing a closure system in which both a child resistant and key option are available, the key can be utilized if the user has trouble opening the closure due to the driving structures having been exposed to spills of the liquid pharmaceutical.
In view of the above, what is needed therefore is a lockable closure assembly that, while providing a discrete locking system, is efficient to manufacture. Further, a system in which a user has more options of varying degrees of difficulty to open the closure system based on the consumer's particular circumstances, including a key that serves as an effective tool to make the closure system easy to open and close when used, is desired.